4. (a) Draw an activity network described in this precedence table, using as few dummies as possible.
| Activity | Must be preceded by: |
| A | - |
| B | A |
| C | A |
| D | A |
| E | C |
| F | C |
| G | B, \(D , E , F\) |
| H | \(B , D , E , F\) |
| I | F, \(D\) |
| J | G, H, I |
| K | \(F , D\) |
| L | \(K\) |
- A different project is represented by the activity network shown in Fig. 3. The duration of each activity is shown in brackets.
\begin{figure}[h]
\captionsetup{labelformat=empty}
\caption{Figure 3}
\includegraphics[alt={},max width=\textwidth]{75ea31c7-11e7-4dd9-9312-4cf32bba622b-05_710_1580_1509_239}
\end{figure}
Find the range of values of \(x\) that will make \(D\) a critical activity.
(2)